Galvanomagnetic effect of submicron exchange-coupled Co/Ni wire

The galvanomagnetic effect of an exchange-coupled Co/Ni wire on a submicron scale was investigated by comparing it with the galvanomagnetic effects of single-layered Ni and Co wires. The observed longitudinal magnetoresistance of the Co/Ni wire resembled that of the single-layered Co wire. In the Co/Ni wire, abrupt Hall resistance changes due to the planar Hall effect were observed and were as large as that of the single-layered Co wire. The Hall resistance slopes of the Co/Ni wire due to the extraordinary Hall effect of the Ni layer were also observed, and were smaller than that of the single-layered Ni wire because of the exchange interaction from the Co layer. It was found that, in a low magnetic field, the magnetization processes of both the Ni and Co layers in the Co/Ni wire were almost the same, and were in agreement with that of the single-layered Co wire which is as thick as the Co layer in the Co/Ni wire.